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Question

A spray tube (6cm2) has 30 holes of diameter 1.2mm. If the flow speed is 1.8m/min, what is the ejection speed?

Options

Choose one · Correct answer highlighted

Explanation

A1v1 = A2v2, v1 = 1.8m/min = 0.03m/s, A1 = 6×10−4m2. Hole area: Ah = π(0.6×10−3)2, total A2 = 30×π×3.6×10−7≈3.39×10−5m2. v2 = 6×10−4×0.033.39×10−5≈0.531m/s. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 0.53 m/s. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.